Shoe stiffener and art of manufacturing it



March 1929. w. H. BANCROFT ET AL 1,704,8

SHOE STIFFENER AND ART OF MANUFACTURING IT Filed Dec. 31, 1924 4 IIIIII-IIIIIII QM i /NVENTL7R5.

Patented Mar. f2, 1929..

UNITED STATES PATENT OFFICE.

WILLIAM HAROLD BANc oE'r, WILLIAM .IAcxsoN LUNn, AND mAUnrcE GODFREYHILL, or LEICESTER, ENGLAND, ASSIGNORS T0 UNITED SHOE MACHINERY conPOBATION, 0E PATERSON, NEW JERSEY, A CORPORATION on NEW JERSEY.

sHOE STIFFENER AND ART OF MANUFACTURING I'll.

Application filed December 81, 1924, Serial No. 759,684, and in GreatBritain January 22, 1924.

This invention relates to a method of and a machine for operating uponstiffenersfor boots and shoes and to a completed stiffener.

It is desirable that box toes for use in certain kinds of shoes, andparticularly for use in so=called plain-teed shoes which have no toe capor tip, should be very flexible along their rear margins; sinceotherwise an objectionable ridge is liable to appear across the toe ofthe finished shoe.

A box toe which is very largely used inv the manufacture of shoesconsists of a piece of fibrous material impregnated with a thermoplasticstifi'ener substance,-that is, with a substance such, for example, as amixture of 90 er cent of rosin and 10 per cent of carnau ha wax, whichis normally stiff and resilient but may be rendered plastic or molten byheat. The rear margins of these box toes are commonly skived to rendersaid margins less bulky and more flexible, but the margins so treatedhave proved'to be too stiff and inflexible to be used satisfactorily inplain-toed shoes.

' In one aspect, the invention comprises a method in which theimpregnant substance, or at least the greater part of it, is squeezedout of a selected margin of the stifli'ener, while said substance issufficiently soft, by pressure appliedprogressively across the margintoward the edge thereof. Preferably the pressure is a rolling one; and,in the case of a thermoplastic stifi'ener, the impregnant substance 1ssoftened by being melted. By applying the pressure pro-m gressively froma locality in the body portion of the stifiener across the margin, saidmargin is thinned without the formation of a ridge of pressed-outimpregnant substance such as might occur if the pressure were applied,for example, progressively in the opposite direction.

In another aspect, the invention relates to a machine for carrying outthe method comprising a pair of co-operating rolls, one or both of whichmay be heated, .one of said rolls having a stiffener-receiving matrix solocated and of such shape and size that the proper progressive rollingKpressure will be a plied to the margin of t e blank. Prefera ly thematrix will be made somewhat smaller than the. stiffener so that part ofthe marginof the stifiener will extend outside the matrix in position tobe pressed between cylindrical portions of the rolls, such aconstruction resulting in the production of a 'stifiener .the extrememargin of which is very pliable.

In still another aspect, the invention relates to a completed stiffener.

Referring now to the accompanying drawings,

Figure 1 is a view principally in crosssection of a portion of a machinefor. treatingFbox toe blanks;

igure 2 is a development of a portion of the surface of the matrix rollshowing a box toe blank in place, but without having been operated upon;A

Figure 3 1s a cross-section on the line 3-3 of Figure 2 viewed in thedirection indi-.

cated by the arrow; and

Figure 4 is a cross-section of a finished box toe. Y

The machine comprises two metal rolls 5 and 7 between which the box toesare fed,

said rolls being chambered to permit steam to be passed through them toheat them as indicated by the small arrows in Figure 1. The box toeblanks 100 to be treated are stacked in a magazine, the rear wall ofwhich is made up of; two parts 9 and 11, the part 9 being adjustableverticall to provide for box toe blanks of different t icknesses. Apresser 13 rests upon the stack, and a feed slide 15 is reciprocated tofeed the blanks one by one-in proper timed rela tion to the rolls 5 and7 Any suitable mechanism may be employed to rotate the rolls and tooperate the slide such, for ex? ample, as that shown in the patent toScott The lower roll 7 is provided with a matrix 17. As shown in Figures2 and 3, the matrix or recess 17 is cut with beveled edges all around,the bevel along the rear edge, as

shown at 19, being of a comparatively long taper. Furthermore, therecess is of a size and shape to allow some measurable width (say 4 inchon blanks of medium size) of the rear margin of the blank to project beyond the corresponding edge 21 of the matrix and thus be gripped, as therolls rotate, between cylindrical portions of the rolls. Figure 1 showsa blank of which the rear edge is thus gripped, and Figure 4 shows theresult, the rear edge portion of the blank having been practicallyentirely freed of impregnant by the roll pressure. In Figure 3 the blankis shown fully laid into the matrix but without the resulting action ofpressure upon its edges.

Spikes 22 are preferably placed in the matrix to prevent any possibilityof the blank shifting relatively to the matrix during its passagebetween the rolls.

A scraper 23 is conveniently arranged against the under side of thematrix roll to remove the expressed impregnant; and, in,

order to secure regular delivery of the blanks from the rolls (theblanks being at this time entirely limp owing to their heatedcondition), a tray 25 provided with an upstanding lip 27 is placed belowand to the rearof the lower roll. As each blank emerges from the bite ofthe rolls, its leading edge tends to part from the matrix and thusengages the lip of the tray at about the same instant that the rear edgeof the blank leaves the bite. This causes the blank to fall over flatupon the tray with its rear edge away from the rolls'as shown by theblank 100 in Figure 1. The rear wall of the magazine may be insulated ifdesired, so as to keep.the stack of blanks cold in order that they maybe fed with due regularity into the bite of the rolls, it beingunderstood that the rolls are brought to a temperature suflicient fullyto melt the impregnant in the blank as the blank passes between them.

By suitably shaping the matrix, the point at which themargin-thinning-pressure between the rolls becomes eifectlve can beaccurately determined and the pressure can with nicety be increased asthe back edge of the blank is gradually reached, so that a very gradualincrease in pliability ,of the blank towards its back edge can beattained.

. The use of a matrix recess also enables the thinning'to be performedalong a curved line following that of the edge of the blank itself, aresult not obtainable by plain rolling action conducted across a curvededge.

Provided adequate heat and pressure be employed, the method describedabovema be used with advantage to replace wholly the skiving or similartreatment of the margin of blanks which has been hitherto consideredessential. Not only is the margin so thinned more pliant than oneobtained in the cus whole of the periphery of the blank if desired andis obviously not limited in its anplication to the back edge of theblank. In this connection it will be observed that the matrix of Figure3 is bevelled off around the whole of its edge, the bevel being a shortin cline around the front and side edges of the blank as compared withthat along the rear edge since, although extreme flexibility is notnecessary around the front and side edges, a thinning of the edge atthese parts is generally desirable and can be obtained simultaneouslywith the treatment of the rear edge of the blank without any additionalexpenditure of time or labor. It will be apparent, however, that themethod above described may be employed to advantage upso on blanks that,possibly on account of their being made of special material, have beenskived.

Having thus described our invention,

what we claim as new and desire to secure by Letters Patent of theUnited States is:

1. The method of producing a thin pliable margin on a stiffener blankmade of fibrous material impregnated with a stiffen- 1 g substance whichconsists in applying no pressure progressively across the margin towardthe edge thereof to express impreg-n nant substance from themargin.

2. The method of producing a thin pliable margin on a stiffener blankmade of fibrous 3. The method of producing a thin pliable margin on astiffener blank made of fibrous material impregnated with athermoplastic substance which consists in melting the substance andapplying pressure progressively across the margin toward the edge withsufficient force to express impregnant substance from the margin;

4. The -method of producing a thin pliable margin on a stifiener blankmade of fibrous material impregnated with a thermoy plastic substancewhich consists in melting the substance and applying rolling pressureprogressively across the margin toward the edge with sufficient force toexpress impregnant substance from the margin.

5. A machine for thinning a margin of a shoe stifiener made of a pieceof fibrous material impregnated with a thermoplastic stiffeningsubstance having, in combination, a pair'of co-operating rotary rolls,one of said rolls having a matrix, and means for heating the rolls to atemperature suflicient to melt the impregnant substance. 7

6. A machine for thinning a margin of a shoe stiflener made of a pieceof fibrous material impregnated with a thermoplastic stifi'eningsubstance having, in combination a pair of co-operating rotarv rolls,one o said rolls having a matrix, means for heat-- ing the rolls to atemperature suflicient to melt the impregnant substance, and means forfeeding stifii'eners to the rolls.

7. A machine for treating stiifeners made of a piece of fibrous materialimpregnated with a thermoplastic stiffening substance having, incombination, a pair of co-operating rotary rolls, one of said rollshaving a matrix, and means for heating the rolls to a temperaturesufficient to melt the impregnant substance, the relative sizes of thematrix and a stiffener being such that a margin of the stifl'ener willextend outside the matrix.

8. A machine for thinning a margin'of a shoe stiffener made of a pieceof fibrous material impregnated with a thermoplastic stiffeningsubstance having, in combination, a? pair of co-operating rotary rolls,one of said rolls having a matrix the depth of the greater portion ofwhich is substantially equal to the thickness ofthe stiffener, the depthof the matrix at a marginal portion thereof decreasing gradually towardthe edge thereof so as to cause progressively increasing pressure to beapplied to that portion of the stifi'ener which is received in saidmarginal portion, and means for heating one of sald rolls. s

In testimony whereof we have signed our names to this specification.

WILLIAM'HAROLD BANOROF'YI. WILLIAMJACKSON LUND. MAURICE GODFREY HILL.

